Telephone transmitter



J. P. MINTON TELEPHONE /APPLICATION FILED MAR. 2T, 1918.

AND C. A. FINLE-Y.

TRANSMITTER.

- Patented 0st. 241. 31922.

TOEN l. MINTDN. 0F EAST ORANGE. NEW JERSEY, .AND CHARLES A. FINLEY. 0F

BROOKLYN, NEW YORK.. ASSIGNORS TO WESTERN ELECTRIC COMPANY. NCOR-EGE-ATER GI NEW- EQRK, Yi. A CORPORATION OF NEW YRK.

TELEIEHGNE TRANSMITTER.

.Application filed Marc-n 27, 1818. Serial No. 224,981.

lie it known that We, .imm l). iliiNToN and (unimaas A. Finney, citizensof the United States, residing at East Orange, in the county of Essexand Stute ot New Jersey, and at Brooklyn, in the county of Kings andState of New York, respectively, have invented certain new and usefulimprovements in Telephone Transmitters, of which the following is a.full, clear, concise, and exact description. f

This invention relates in general to tel phone transmitters, and morespecifically a transmitter particularly suitable for u in placessubjected to severe extraneous noises or to vibrations set up by therush of Wind.'

i in many cases it is importent that a transmitter be provided which'will be sensitive and eihcient in operation and yet one which will notbe interfered with by excessive noises or violent explosions occurringYclose by. Such are the requirements, ior example, for a, transmitter 'tobe used in connection with telephone sets on aeroplanes forrommnnicaftion between the pilot und the obrer or 'for Wirelesscommunication with .aber stations. llnder siich cond ons the violentdisturbances set up by 'the exhaust of the engines and the rush oi"l airmalle di i l le,

e.. to

recraudible conversation impossi. und it luis been necessary resort to iuse oil teleplii'ines for communication. However. to 'nin satisfactorytransmission it has lu reto-i'ore been necessary to shield tbetransmitter by mount-ingr it in a. practically sound proof box intowhich the use-r musi thrust, his face vvlen talking'. Such anarrangement .is not only awkward and cumbersome but quite likely tointeriore with the other duties or" the user, as Well as obstruct hisvision. Again, for use with-lire control on bati'lesbips or landfortifications, there is de ined need for a transmitter which willeasily and. intelligibly transmit speech in spire oi the if'iolent.concussione due 'to the discharge 'oi batteries nearby.

it is thereiori he object oi tli present in.- "fention to pr: 'i 'le a'telephone transmitter which will not be susceptible to disturbingnoisesor .i'l'iistlingg' resulting; from the action ci the Wind when thetransmitter is exposed i the open, or to the rush of one which will beefficient in transmission,

cheap of manufacture and -Which will be free from all delicateadgustments necessitating expert attention.A

To accomplish the above objects :i feature of the present inventionresides in equipping a transmitter with a face plate in which areprovided a plurality of holes or pcrlioraiions small in diameter.

Another 'feature consists in providing a very small rcsonatingr chamber7that is. mii-l:- ing' the clearance between the diapliragn. and the iaceplate very small to further aid in preventing outside disturbancesaii'ecting the diaphragm.

Other objects and features of the invention will loe apparent from thefollowing description, und will be particularly pointed out in theappended claims.

The .invention is illustrated in the accompanying drawing' in which Fig.l is uA sectional vieu of a transmitter embodying this invention; andFig. 2 isa front' View of 'the trani-imiter shown in Fig. l and having aportion oi. the iace plate" removed to more" clearly shon the internalconstruction.

Referring now to the drawing, there is provided a casingF 5 to Whichtloeface late il is secured by means of screws 7"?. lince the tace plete andcasing' are preferably made of aluminum, it has been found advisable toemploy shouldered studs 8 8 of German silver or similar material andthreaded to receive the screws 7-7. The rinz;r 9 is clamped between theface plate 6 and the casing The face plate 6 is perforated with a largenumber of evenly distributed perforations l010 which are small indiameter in comparison with the thickness of the face plate. inpractice, it has been oundthat very satis-:Factor i results are obtainedwhen the diameter oil these per- ;'oiations is .O50 inches or less. andthe thickness of the face 'plate is not less than oneeighth oi an inch.The inner side of the face plate is counter-bored to receive the dia-Y.. in.

Lion of he' bridge-came? Li- :md-61h@ mica Wa'im l' is a mslnl plaie l??having am 2X- imfeii portion provided Wilh he iisfliinai screw iii), Thehi'idge cents? is bored mit o rifive the shank of :i standar@ type oftransmita' button Qhziprsing :l cup mem.-

ih piace by mit ammini; mi] .I'esiiicfr@ @Minimum would i? i iiiiiii, L.

HNiziiCiiiUg with plais.

2i. in. ii, iifim-lmii" :i ihzii'lh'nggm mi: im? piatti w WKN 1 1minuten my it; heling a i f 5. n a transmitter, a face nlate havin aplurality of small openings therethrougi\1 the diameter off Saidperforations being' less than the thickness of the face plate; and adiaphragm,'spaced adjacent thereto but separated therefrom to provide athin i'esenating' ithamber having; a depth not greater than .O15 inchescommunicating' with the openings in said vface plate.

6. 1n a transmitter, a easing, a transmitter 'button having` a cupmember in lwhich are located thefront and back electrodes practicallyfiiled with granular carbon', means for snpponting said button in saidcasing a diaphragm hating a high natural period., spring means formaintaining said hutten in engagement with said diaphragm, and Jfaceplate having a plurality of small openings whereby Violent Vibrations ofair external to the transmitter are prevented from actuating saiddiaphragm.

7. A transmittercomprising a. face plate, a diaphragm mounted infafe-n-iace relation with said plan. and means invluding a plurality ofsmall and relativeiy deep per'- iuorations through said plate otl'ering:l large amount oi suri'ave lirietion to the passage of presi-:urerairiaiions therethrough to shield the diaphra'i from Sudden and violentprix sur@ eliai i transmitter yComprisingr a cup, a relatively thirkflat plate forming a @over for said wup, a diaphragm mounted in closefaceto-fac'e relation to said plate within said cup. and a plurality ofrelatively small-pew fomit-ions of uniform depth extending through saidplate,

in witness whereof, we herennto suhserihe our naines this 25th day ofMarch, A. D., 1918.

Jona P, Minaccia. @Hannes A. einem.

